diff --git a/arch/arm/mach-shmobile/pm-r8a7779.c b/arch/arm/mach-shmobile/pm-r8a7779.c
index d5f258e4d890..47a862e7f8ba 100644
--- a/arch/arm/mach-shmobile/pm-r8a7779.c
+++ b/arch/arm/mach-shmobile/pm-r8a7779.c
@@ -35,7 +35,8 @@ struct r8a7779_pm_domain {
 	struct rcar_sysc_ch ch;
 };
 
-static inline struct rcar_sysc_ch *to_r8a7779_ch(struct generic_pm_domain *d)
+static inline
+const struct rcar_sysc_ch *to_r8a7779_ch(struct generic_pm_domain *d)
 {
 	return &container_of(d, struct r8a7779_pm_domain, genpd)->ch;
 }
diff --git a/arch/arm/mach-shmobile/pm-rcar.c b/arch/arm/mach-shmobile/pm-rcar.c
index 00022ee56f80..4092ad16e0a4 100644
--- a/arch/arm/mach-shmobile/pm-rcar.c
+++ b/arch/arm/mach-shmobile/pm-rcar.c
@@ -15,32 +15,58 @@
 #include <asm/io.h>
 #include "pm-rcar.h"
 
-/* SYSC */
-#define SYSCSR 0x00
-#define SYSCISR 0x04
-#define SYSCISCR 0x08
+/* SYSC Common */
+#define SYSCSR			0x00	/* SYSC Status Register */
+#define SYSCISR			0x04	/* Interrupt Status Register */
+#define SYSCISCR		0x08	/* Interrupt Status Clear Register */
+#define SYSCIER			0x0c	/* Interrupt Enable Register */
+#define SYSCIMR			0x10	/* Interrupt Mask Register */
 
-#define PWRSR_OFFS 0x00
-#define PWROFFCR_OFFS 0x04
-#define PWRONCR_OFFS 0x0c
-#define PWRER_OFFS 0x14
+/* SYSC Status Register */
+#define SYSCSR_PONENB		1	/* Ready for power resume requests */
+#define SYSCSR_POFFENB		0	/* Ready for power shutoff requests */
 
-#define SYSCSR_RETRIES 100
-#define SYSCSR_DELAY_US 1
+/*
+ * Power Control Register Offsets inside the register block for each domain
+ * Note: The "CR" registers for ARM cores exist on H1 only
+ *       Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
+ */
+#define PWRSR_OFFS		0x00	/* Power Status Register */
+#define PWROFFCR_OFFS		0x04	/* Power Shutoff Control Register */
+#define PWROFFSR_OFFS		0x08	/* Power Shutoff Status Register */
+#define PWRONCR_OFFS		0x0c	/* Power Resume Control Register */
+#define PWRONSR_OFFS		0x10	/* Power Resume Status Register */
+#define PWRER_OFFS		0x14	/* Power Shutoff/Resume Error */
 
-#define SYSCISR_RETRIES 1000
-#define SYSCISR_DELAY_US 1
+
+#define SYSCSR_RETRIES		100
+#define SYSCSR_DELAY_US		1
+
+#define PWRER_RETRIES		100
+#define PWRER_DELAY_US		1
+
+#define SYSCISR_RETRIES		1000
+#define SYSCISR_DELAY_US	1
 
 static void __iomem *rcar_sysc_base;
 static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
 
-static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch,
-				int sr_bit, int reg_offs)
+static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
 {
+	unsigned int sr_bit, reg_offs;
 	int k;
 
+	if (on) {
+		sr_bit = SYSCSR_PONENB;
+		reg_offs = PWRONCR_OFFS;
+	} else {
+		sr_bit = SYSCSR_POFFENB;
+		reg_offs = PWROFFCR_OFFS;
+	}
+
+	/* Wait until SYSC is ready to accept a power request */
 	for (k = 0; k < SYSCSR_RETRIES; k++) {
-		if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit))
+		if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
 			break;
 		udelay(SYSCSR_DELAY_US);
 	}
@@ -48,27 +74,17 @@ static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch,
 	if (k == SYSCSR_RETRIES)
 		return -EAGAIN;
 
-	iowrite32(1 << sysc_ch->chan_bit,
+	/* Submit power shutoff or power resume request */
+	iowrite32(BIT(sysc_ch->chan_bit),
 		  rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
 
 	return 0;
 }
 
-static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch)
+static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
 {
-	return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS);
-}
-
-static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch)
-{
-	return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS);
-}
-
-static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
-			    int (*on_off_fn)(struct rcar_sysc_ch *))
-{
-	unsigned int isr_mask = 1 << sysc_ch->isr_bit;
-	unsigned int chan_mask = 1 << sysc_ch->chan_bit;
+	unsigned int isr_mask = BIT(sysc_ch->isr_bit);
+	unsigned int chan_mask = BIT(sysc_ch->chan_bit);
 	unsigned int status;
 	unsigned long flags;
 	int ret = 0;
@@ -78,15 +94,26 @@ static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
 
 	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
 
-	do {
-		ret = on_off_fn(sysc_ch);
+	/* Submit power shutoff or resume request until it was accepted */
+	for (k = 0; k < PWRER_RETRIES; k++) {
+		ret = rcar_sysc_pwr_on_off(sysc_ch, on);
 		if (ret)
 			goto out;
 
 		status = ioread32(rcar_sysc_base +
 				  sysc_ch->chan_offs + PWRER_OFFS);
-	} while (status & chan_mask);
+		if (!(status & chan_mask))
+			break;
 
+		udelay(PWRER_DELAY_US);
+	}
+
+	if (k == PWRER_RETRIES) {
+		ret = -EIO;
+		goto out;
+	}
+
+	/* Wait until the power shutoff or resume request has completed * */
 	for (k = 0; k < SYSCISR_RETRIES; k++) {
 		if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
 			break;
@@ -106,22 +133,22 @@ static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
 	return ret;
 }
 
-int rcar_sysc_power_down(struct rcar_sysc_ch *sysc_ch)
+int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch)
 {
-	return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_off);
+	return rcar_sysc_power(sysc_ch, false);
 }
 
-int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch)
+int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch)
 {
-	return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_on);
+	return rcar_sysc_power(sysc_ch, true);
 }
 
-bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch)
+bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
 {
 	unsigned int st;
 
 	st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
-	if (st & (1 << sysc_ch->chan_bit))
+	if (st & BIT(sysc_ch->chan_bit))
 		return true;
 
 	return false;
diff --git a/arch/arm/mach-shmobile/pm-rcar.h b/arch/arm/mach-shmobile/pm-rcar.h
index ef3a1ef628f1..1b901db4a24c 100644
--- a/arch/arm/mach-shmobile/pm-rcar.h
+++ b/arch/arm/mach-shmobile/pm-rcar.h
@@ -2,14 +2,14 @@
 #define PM_RCAR_H
 
 struct rcar_sysc_ch {
-	unsigned long chan_offs;
-	unsigned int chan_bit;
-	unsigned int isr_bit;
+	u16 chan_offs;
+	u8 chan_bit;
+	u8 isr_bit;
 };
 
-int rcar_sysc_power_down(struct rcar_sysc_ch *sysc_ch);
-int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch);
-bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch);
+int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch);
+int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch);
+bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch);
 void __iomem *rcar_sysc_init(phys_addr_t base);
 
 #endif /* PM_RCAR_H */
diff --git a/arch/arm/mach-shmobile/smp-r8a7779.c b/arch/arm/mach-shmobile/smp-r8a7779.c
index 01f792fcb220..9122216df060 100644
--- a/arch/arm/mach-shmobile/smp-r8a7779.c
+++ b/arch/arm/mach-shmobile/smp-r8a7779.c
@@ -32,25 +32,25 @@
 #define AVECR IOMEM(0xfe700040)
 #define R8A7779_SCU_BASE 0xf0000000
 
-static struct rcar_sysc_ch r8a7779_ch_cpu1 = {
+static const struct rcar_sysc_ch r8a7779_ch_cpu1 = {
 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
 	.chan_bit = 1, /* ARM1 */
 	.isr_bit = 1, /* ARM1 */
 };
 
-static struct rcar_sysc_ch r8a7779_ch_cpu2 = {
+static const struct rcar_sysc_ch r8a7779_ch_cpu2 = {
 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
 	.chan_bit = 2, /* ARM2 */
 	.isr_bit = 2, /* ARM2 */
 };
 
-static struct rcar_sysc_ch r8a7779_ch_cpu3 = {
+static const struct rcar_sysc_ch r8a7779_ch_cpu3 = {
 	.chan_offs = 0x40, /* PWRSR0 .. PWRER0 */
 	.chan_bit = 3, /* ARM3 */
 	.isr_bit = 3, /* ARM3 */
 };
 
-static struct rcar_sysc_ch *r8a7779_ch_cpu[4] = {
+static const struct rcar_sysc_ch * const r8a7779_ch_cpu[4] = {
 	[1] = &r8a7779_ch_cpu1,
 	[2] = &r8a7779_ch_cpu2,
 	[3] = &r8a7779_ch_cpu3,
@@ -66,7 +66,7 @@ void __init r8a7779_register_twd(void)
 
 static int r8a7779_platform_cpu_kill(unsigned int cpu)
 {
-	struct rcar_sysc_ch *ch = NULL;
+	const struct rcar_sysc_ch *ch = NULL;
 	int ret = -EIO;
 
 	cpu = cpu_logical_map(cpu);
@@ -82,7 +82,7 @@ static int r8a7779_platform_cpu_kill(unsigned int cpu)
 
 static int r8a7779_boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	struct rcar_sysc_ch *ch = NULL;
+	const struct rcar_sysc_ch *ch = NULL;
 	unsigned int lcpu = cpu_logical_map(cpu);
 	int ret;
 
diff --git a/arch/arm/mach-shmobile/smp-r8a7790.c b/arch/arm/mach-shmobile/smp-r8a7790.c
index 930f45cbc08a..2ef0054ce934 100644
--- a/arch/arm/mach-shmobile/smp-r8a7790.c
+++ b/arch/arm/mach-shmobile/smp-r8a7790.c
@@ -26,12 +26,12 @@
 #include "rcar-gen2.h"
 #include "r8a7790.h"
 
-static struct rcar_sysc_ch r8a7790_ca15_scu = {
+static const struct rcar_sysc_ch r8a7790_ca15_scu = {
 	.chan_offs = 0x180, /* PWRSR5 .. PWRER5 */
 	.isr_bit = 12, /* CA15-SCU */
 };
 
-static struct rcar_sysc_ch r8a7790_ca7_scu = {
+static const struct rcar_sysc_ch r8a7790_ca7_scu = {
 	.chan_offs = 0x100, /* PWRSR3 .. PWRER3 */
 	.isr_bit = 21, /* CA7-SCU */
 };